<template>
  <div class="sub-filter" v-if="filterData && !filterLoading">
    <div class="item">
      <div class="head">品牌：</div>
      <div class="body">
        <a
          :class="{ active: filterData.selectedBrand === brand.id }"
          href="javascript:;"
          v-for="brand in filterData.brands"
          @click="changeBrand(brand.id)"
          :key="brand.id"
          >{{ brand.name }}</a
        >
      </div>
    </div>
    <div class="item" v-for="p in filterData.saleProperties" :key="p.id">
      <div class="head">{{ p.name }}：</div>
      <div class="body">
        <a
          :class="{ active: p.selectedProp === attr.id }"
          href="javascript:;"
          v-for="attr in p.properties"
          :key="attr.id"
          @click="changeProp(p, attr.id)"
          >{{ attr.name }}</a
        >
      </div>
    </div>
  </div>
  <div v-else class="sub-filter">
    <XtxSkeleton class="item" width="800px" height="40px" />
    <XtxSkeleton class="item" width="800px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
    <XtxSkeleton class="item" width="600px" height="40px" />
  </div>
</template>
<script>
import { findSubCategoryFilter } from "@/api/category";
import { useRoute } from "vue-router";
import { ref, watch } from "vue";
export default {
  name: "SubFilter",
  setup(props, { emit }) {
    // 1. 获取数据
    // 2. 数据中需要全部选中，需要预览将来点击激活功能。默认选中全部
    // 3. 完成渲染
    const route = useRoute();
    const filterData = ref(null);
    const filterLoading = ref(false);
    // 4. 分类发生变化的时候需要重新获取筛选数据，需要使用侦听器
    watch(
      () => route.params.id,
      (newVal, oldVal) => {
        // 当你从二级分类去顶级分类也会拿到ID，不能去加载数据因为它不是二级分类的ID
        if (newVal && route.path === "/category/sub/" + newVal) {
          filterLoading.value = true;
          newVal &&
            findSubCategoryFilter(route.params.id).then(({ result }) => {
              // 品牌全部
              result.selectedBrand = null;
              result.brands.unshift({ id: null, name: "全部" });
              // 销售属性全部
              result.saleProperties.forEach((p) => {
                p.selectedProp = null;
                p.properties.unshift({ id: null, name: "全部" });
              });
              filterData.value = result;
              filterLoading.value = false;
            });
        }
      },
      { immediate: true }
    );
    const getFilterParams = () => {
      const obj = { brandId: null, attrs: [] };
      // 品牌
      obj.brandId = filterData.value.selectedBrand;
      // 销售属性
      filterData.value.saleProperties.forEach((item) => {
        if (item.selectedProp) {
          const prop = item.properties.find(
            (prop) => prop.id === item.selectedProp
          );
          obj.attrs.push({ groupName: item.name, propertyName: prop.name });
        }
      });
      // 参考数据：{brandId:'',attrs:[{groupName:'',propertyName:''},...]}
      if (obj.attrs.length === 0) obj.attrs = null;
      return obj;
    };
    // 1. 记录当前选择的品牌
    const changeBrand = (brandId) => {
      if (filterData.value.selectedBrand === brandId) return;
      filterData.value.selectedBrand = brandId;
      emit("filter-change", getFilterParams());
    };
    // 2. 记录呢选择的销售属性
    const changeProp = (item, propId) => {
      if (item.selectedProp === propId) return;
      item.selectedProp = propId;
      emit("filter-change", getFilterParams());
    };
    return {
      filterData,
      filterLoading,
      getFilterParams,
      changeBrand,
      changeProp,
    };
  },
};
</script>
<style scoped lang="less">
// 筛选区
.sub-filter {
  .xtx-skeleton {
    padding: 10px 0;
  }
  background: #fff;
  padding: 25px;
  .item {
    display: flex;
    line-height: 40px;
    .head {
      width: 80px;
      color: #999;
    }
    .body {
      flex: 1;
      a {
        margin-right: 36px;
        transition: all 0.3s;
        display: inline-block;
        &.active,
        &:hover {
          color: @xtxColor;
        }
      }
    }
  }
}
</style>
